Abstract: Provided are a characteristic signal injection method and device suitable for active detection-based protection, which are applied to a distributed power supply. The distributed power supply is connected to a power distribution grid system.

Abstract: Disclosed are a single-phase-to-ground protection method and system for an active power distribution network. The method includes: acquiring current and voltage data of a line in real time by means of a power distribution terminal, and calculating active power of the line; recording and storing the active power of the line to form an active power curve; performing data statistics according to the active power curve; calculating a direction compensation coefficient and a zero-sequence current compensation coefficient on the basis of statistical data; and detecting whether a single-phase-to-ground fault occurs to the line, where when the single-phase-to-ground fault occurs to the line, a transient-state zero-sequence direction and a steady-state zero-sequence direction are compensated, or a zero-sequence current is compensated, it is determined that the single-phase-to-ground fault occurs to the line when compensation results satisfy action conditions, and tripping is performed or an alarm is given.

Abstract: Disclosed are a single-phase-to-ground protection method and system for an active power distribution network. The method includes: acquiring current and voltage data of a line in real time by means of a power distribution terminal, and calculating active power of the line; recording and storing the active power of the line to form an active power curve; performing data statistics according to the active power curve; calculating a direction compensation coefficient and a zero-sequence current compensation coefficient on the basis of statistical data; and detecting whether a single-phase-to-ground fault occurs to the line, where when the single-phase-to-ground fault occurs to the line, a transient-state zero-sequence direction and a steady-state zero-sequence direction are compensated, or a zero-sequence current is compensated, it is determined that the single-phase-to-ground fault occurs to the line when compensation results satisfy action conditions, and tripping is performed or an alarm is given.